Uma dica rápida, para adicionar os repositórios do RPM Forge no CentOS.

CentOS 5

32 bits:

# rpm -ivh http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el5.rf.i386.rpm

64 bits:

# rpm -ivh http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el5.rf.x86_64.rpm

CentOS 6

32 bits:

# rpm -ivh http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.i686.rpm

64 bits:

# rpm -ivh http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm

E agora, atualize:

# yum update


Espero que ajude.

Guia de referência para essa dica:

• Install and Enable RPMForge Repository in RHEL/CentOS 6, 5, 4